[coreboot] [v3][patch] Add early MTRR setup

Carl-Daniel Hailfinger c-d.hailfinger.devel.2006 at gmx.net
Sat Feb 7 12:05:37 CET 2009


On 06.02.2009 23:37, Marc Jones wrote:
> Setup the MTRRs in stage1 so that memory and cache are available throughout
> stage2. This fixes problems with VGA graphics ROMs access to 0xA0000-0xBFFFF.
> It also sets all system memory to WriteBack cached and sets the ROM
> area to cached.
>
> Signed-off-by: Marc Jones <marcj303 at gmail.com>
>   

The code looks scary, especially the part where you disable cache
although memory may not be set up completely yet. Can you explain why
that is not a problem? Thanks.

My general principle is "don't fiddle with cache settings until you know
RAM is fine".

Regards,
Carl-Daniel

-- 
http://www.hailfinger.org/





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